1. Field of the Invention
The present invention relates in general to rack and pinion steering gears for road vehicles and more particularly to a protective boot or rubber boot for covering an end of a rack gear and a ball joint through which the rack gear is joined to a tie rod.
2. Description of the Prior Art
There has been proposed by the Japanese Provisional Patent Publication No. 58-97561 a road vehicle rack and pinion steering gear that can be designed so as to effect a desired suspension characteristic even when its gear train (pinion, rack gear, gear housing, etc.) must be placed in a certain limited position so as to not to interfere or contact with an adjacent transmission, etc.
In the steering gear, a ball joint which joins an end of a rack gear to a tie rod is adapted to have a center of rotary motion which is offset from the center axis of the rack gear so that a steering linkage (tie rod, knuckle arm, etc.) can be arranged at a place not interfering or contacting with a suspension, etc. and at the same time enabling the steering gear to effect a desired suspension characteristic.
The ball joint includes a ball member ending in a ball and arranged so that the axis of the ball member is perpendicular to the center axis of the rack gear. The ball member has a tapered shank fitted in a correspondingly shaped transverse hole in the rack gear and fastened thereto by a nut.
Such a steering gear has a problem that it requires a plurality of rubber boots or a complicatedly shaped rubber boot for covering the end of the rack gear and the ball joint, resulting in an increased number of constituent parts or a deteriorated durability of the rubber boot.